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Biomedical subjects

E Beattie

Publications and source records attributed to E Beattie.

12 recordsLinked to original sources

A Delphi study to identify performance indicators for emergency medicine.

OBJECTIVES: The aim of this study was to identify performance indicators thought to reflect the quality of patient care in the emergency department. METHODS: A three round accelerated Expert Delphi study was conducted by email or fax. A panel of 33 experts drawn from the fields of emergency medicine, emergency nursing, professional service users, and patients were consulted. Participants were initially asked to propose performance indicators that reflected the quality of care given in the emergency department setting in the United Kingdom. In the second round these proposals were collated and scored using a 9 point Likert scale; those that had not reached consensus were returned for reconsideration in the light of group opinion. Those statements reaching a pre-defined consensus were identified. RESULTS: 224 performance indicators were proposed. Altogether 36 indicators reached consensus reflecting good departmental performance after round three; 24 of these were process measures. CONCLUSIONS: 36 potential indicators of good quality of care in the emergency department in the UK have been identified.

Delphi Technique↗

Tales from the crypt: evidence for heptahelical receptor signaling in the endocytic pathway.

In certain circumstances, internalized receptors are able to continue signaling after endocytosis. Whistler et al. discuss how the interaction of heterotrimeric GTP-binding protein (G protein)-coupled receptors with arrestins and their subsequent endocytosis may contribute to activation of the mitogen-activated protein kinase pathway. This perspective delves into the role that scaffolds may play in organizing and specifying downstream signaling events that occur after internalization of G protein-coupled receptors.

Animals↗

Role of the vaccinia virus E3L and K3L gene products in rescue of VSV and EMCV from the effects of IFN-alpha.

Vaccinia virus (VV) has been shown to be relatively resistant to the antiviral effects of interferon-alpha (IFN-alpha) and to rescue replication of IFN-sensitive viruses, such as encephalomyocarditis virus (EMCV) and vesicular stomatitis virus (VSV), from the antiviral effects of IFN. The E3L and K3L gene products have been implicated in the IFN resistance of VV. We have investigated the role that these VV-encoded functions play in the rescue of VSV and EMCV from the effects of IFN. Transient expression of the E3L open reading frame (ORF) was sufficient to rescue VSV but not EMCV from the IFN-induced antiviral state. Rescue of VSV by mutants of E3L correlated with the ability of the mutated E3L gene products to bind dsRNA. Conversely, transient expression of the K3L ORF was sufficient to partially rescue EMCV but not VSV from the effects of IFN. Results with VV deleted of either the K3L or E3L ORFs were consistent with results obtained by transient expression of these genes. These results demonstrate that the VV E3L gene products are likely responsible for the VV-mediated rescue of VSV from the effects of IFN and the K3L gene product is likely at least partly responsible for rescue of EMCV.

Antiviral Agents↗

A signaling organelle containing the nerve growth factor-activated receptor tyrosine kinase, TrkA.

The topology of signal transduction is particularly important for neurons. Neurotrophic factors such as nerve growth factor (NGF) interact with receptors at distal axons and a signal is transduced by retrograde transport to the cell body to ensure survival of the neuron. We have discovered an organelle that may account for the retrograde transport of the neurotrophin signal. This organelle is derived from endocytosis of the receptor tyrosine kinase for NGF, TrkA. In vitro reactions containing semi-intact PC12 cells and ATP were used to enhance recovery of a novel organelle: small vesicles containing internalized NGF bound to activated TrkA. These vesicles were distinct from clathrin coated vesicles, uncoated primary endocytic vesicles, and synaptic vesicles, and resembled transport vesicles in their sedimentation velocity. They contained 10% of the total bound NGF and almost one-third of the total tyrosine phosphorylated TrkA. These small vesicles are compelling candidates for the organelles through which the neurotrophin signal is conveyed down the axon.

Animals↗

Host-range restriction of vaccinia virus E3L-specific deletion mutants.

The vaccinia virus (VV) E3L gene product functions as a dsRNA binding protein that is involved in conferring an interferon-resistant phenotype upon the virus. Studies with a vaccinia virus (VV) E3L- deletion mutant (vP1080) have also demonstrated that the E3L gene product is critical for productive replication on certain cell substrates. While E3L was found to be nonessential for replication in chick embryo fibroblasts (CEFs), virus specifically deleted of E3L was found to be replication deficient in Vero, HeLa, and murine L929 cells. Further, the temporal block in replication appears to differ in these cell systems, as evidenced by the observed timing of protein synthesis inhibition. In Vero cells infected with the VV E3L- mutant, there was no detectable protein synthesis after 2 hr post-infection, whereas in L929 cells normal protein patterns were observed even at late times post-infection. Expression of a heterologous dsRNA binding protein, the reovirus sigma 3 protein, by the E3L- mutant virus restored near wild-type growth characteristics, suggesting the critical nature for regulating dsRNA levels in VV-infected cells.

Animals↗

Distinct patterns of IFN sensitivity observed in cells infected with vaccinia K3L- and E3L- mutant viruses.

Recent results have implicated a role for both the VV K3L- and E3L-encoded gene products in conferring VV with an IFN-resistant phenotype (Beattie et al., Virology 183, 419-422, 1991; Beattie et al., J. Virol. 69, 499-505, 1995). As a means of further establishing the mechanisms by which these functions mediate this process in VV-infected cells, we have further assessed the IFN phenotype in K3L- (vP872) and E3L- (vP1080) virus-infected cells. Biochemical and molecular biological analyses were performed comparing the effects of IFN on wild-type as well as K3L- and E3L- virus-infected cells. Expression analyses of the K3L and E3L gene products revealed that both are evidenced in virus-infected cells as early as 0.5 hr postinfection. E3L expression, however, appears more prolonged, in that it was detectable between 3 to 4 hr postinfection while K3L was undetectable after 3 hr postinfection. Despite having similar expression profiles at early times postinfection, a pronounced sensitivity of protein synthesis to IFN was observed by 30 min postinfection in VV K3L- virus-infected cells, whereas IFN sensitivity was not observed in VV E3L(-)-infected cells until 2 hr postinfection. Subsequent analyses of the IFN-induced antiviral pathways in VV-infected cells demonstrated that the K3L gene product does not contribute to the previously identified specific kinase inhibitory factor (SKIF) activity but does reduce the level of phosphorylated eIF-2 alpha in VV-infected cells. Interestingly, the IFN-induced 2',5'-oligoadenylate synthetase-mediated antiviral pathway was active in VV K3L(-)-infected cells and not in wild-type virus-infected cells. Collectively these results suggest that the K3L(-)- and E3L(-)-encoded products abrogate the antiviral effect of IFN at distinct levels.

2',5'-Oligoadenylate Synthetase↗

Reversal of the interferon-sensitive phenotype of a vaccinia virus lacking E3L by expression of the reovirus S4 gene.

The vaccinia virus (VV) E3L gene, which encodes a potent inhibitor of the interferon (IFN)-induced, double-stranded RNA (dsRNA)-dependent protein kinase, PKR, is thought to be involved in the IFN-resistant phenotype of VV. The E3L gene products, p25 and p20, act as inhibitors of PKR, presumably by binding and sequestering activator dsRNA from the kinase. In this study we demonstrate that VV with the E3L gene specifically deleted (vP1080) was sensitive to the antiviral effects of IFN and debilitated in its ability to rescue vesicular stomatitis virus from the antiviral effects of IFN. Infection of L929 cells with E3L-minus virus led to rRNA degradation typical of activation of the 2'-5'-oligoadenylate synthetase/RNase L system, and extracts of infected cells lacked the PKR-inhibitory activity characteristic of wild-type VV. The reovirus S4 gene, which encodes a dsRNA-binding protein (sigma 3) that can also inhibit PKR activation by binding and sequestering activator dsRNA, was inserted into vP1080. The resultant virus (vP1112) was partially resistant to the antiviral effects of IFN in comparison with vP1080. Further studies demonstrated that transient expression of the reovirus sigma 3 protein rescued E3L-minus VV replication in HeLa cells. In these studies, rescue by sigma 3 mutants correlated with their ability to bind dsRNA. Finally, vP112 was also able to rescue the replication of the IFN-sensitive virus vesicular stomatitis virus in a manner similar to that of wild-type VV. Together, these results suggest that the reovirus S4 gene can replace the VV E3L gene with respect to interference with the IFN-induced antiviral activity.

Animals↗

Chemotherapy rapidly alternating with twice-a-day accelerated radiation therapy in carcinomas involving the hypopharynx or esophagus: an update.

Laboratory studies have suggested that rapidly alternating chemotherapy and radiation therapy might act synergistically. We undertook this study to evaluate the toxicity and effectiveness of this approach in patients with carcinoma involving the hypopharynx or esophagus. Between 1987 and 1991, we treated 47 patients (23 with carcinoma involving the hypopharynx and 24 with carcinoma involving the esophagus) by three cycles of chemotherapy (during weeks 1, 4, and 7) rapidly alternating with twice-a-day radiation therapy (during weeks 2, 5, and 8). Chemotherapy consisted of cisplatin 100 mg/m2 and 5-fluorouracil 3-4 g/m2 given over 4 days. Radiation therapy consisted of 180-200 cGy twice each day to 2000 cGy/cycle, total 6000 cGy over 7 weeks. The histology was squamous cell carcinoma in 44 patients and adenocarcinoma in 3 patients with esophagus cancer. Median follow-up is 2 years (range 1-5 years). The observed survival rate for all 47 patients was 54% at 1 year and 38% at 2 years. Acute toxicity was considerable. Twelve patients (25%) died during therapy from toxicity, without tumor progression, leaving 35 patients (18 hypopharynx, 17 esophagus) evaluable for response. Among the hypopharyngeal patients, 83% had a complete response, 11% had a partial response, and 6% had no response. Among the esophageal patients, 94% had a complete response, and 6% had a partial response. Local control was better for the esophageal patients than the hypopharyngeal patients (98% vs. 52% at 2 years, p = 0.038). The incidence of distant metastases was 25% at 2 years and not significantly different between the two groups. A high rate of local control was achieved, particularly in esophageal cancer, by delivering chemotherapy and radiation therapy in a rapidly alternating fashion. This was achieved at a considerable cost in terms of toxicity, however. Although our response rates and local control compare favorably with those of other recently published studies of combined modality therapy in esophagus or head and neck cancer, much additional work is required to reduce the toxicity and, in hypopharyngeal cancer, to further improve the local control.

Adenocarcinoma↗

Chemotherapy rapidly alternating with accelerated radiotherapy for advanced carcinomas of the hypopharynx and upper esophagus: a feasibility study.

Patients with advanced carcinomas of the hypopharynx or upper esophagus have among the worst prognoses in head and neck oncology. We developed a treatment regimen of rapidly alternating multi-agent chemotherapy and accelerated interrupted radiotherapy as follows: Three cycles of chemotherapy were delivered [day 1, cisplatin 100 mg/m2; days 1-4, 5-fluorouracil (5-Fu) 900 mg/m2] and repeated every 3 weeks. On day 8 of each chemotherapy cycle radiotherapy was started, consisting of 10 fractions of 200 cGy delivered twice daily, for 5 days. The total dose of radiotherapy was 6,000 cGy over 7 weeks, and the total duration of chemotherapy and radiotherapy was 8 weeks. Nineteen patients with locally advanced, epidermoid carcinoma of the hypopharynx (9 patients) or upper esophagus (10 patients) were treated on this protocol. Minimum follow-up was 1 year. Twelve patients had tumors judged technically unresectable, whereas 7 had tumors considered resectable only with total laryngectomy, which was unacceptable to the patients. One patient died of nadir sepsis during treatment, but otherwise the acute toxicity was relatively mild (grade I/II in 16 patients, grade III/IV in 3 patients). The complete response rate was 83% (15 of 18 patients), and the partial response rate was 17% (3 of 18). No patient failed to respond. The survival rate was 80% at 1 year and 73% at 18 months. At 1 year, 89% of the patients remained in remission and at 18 months, 74% Late complications occurred in 4 patients. These included laryngeal necrosis, pneumonitis, esophageal stricture, and tracheoesophageal fistula.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗